Among technologies for manufacturing aluminum alloy wheels, low-pressure casting is a relatively mature one. Moulds (for example, side moulds) for low-pressure casting need to be cooled in the casting process of actual production. Integrated side moulds are commonly adopted in the moulds for low-pressure casting of the wheels and have relatively good effects in practical applications. As the integrated side moulds are simple and convenient to assemble and are relatively low in production cost and maintenance cost, they are widely applied in industrial production.
However, molten aluminum transfers lots of heat to the integrated side moulds in the casting process, thus causing seriously thermal deformation and regular distortion of the side moulds. The deformation and distortion have a serious influence on the precision of matching between the side moulds, between the side moulds and the lower mould and between the side moulds and the upper mould, thus causing problems such as parting-line flashes of matching surfaces and adhesion of aluminum. Since it is difficult to definitely calculate and estimate factors affecting heat expansion and cold contraction of the low-pressure cast aluminum wheels, it is difficult to overcome the dimension error of casting caused by deformation of the moulds by providing allowance in design, and biggish difficulties are also brought in the subsequent machining process.
Meanwhile, the moulds are prone to be locally worn due to the irregular thermal deformation of the moulds, and thus, the service life of the moulds is shortened. In the casting field, the cost of the mould is a very important part of the casting cost. From the point of production practice, 45-degree matching surfaces of the side moulds, i.e., matching surfaces between the side moulds and the upper mould and matching surfaces between the side moulds and the lower mould, are firstly damaged.
It is desirable in the field to overcome this problem by designing a novel mould so as to prolong the service life of the mould, reduce the cost of the mould in production, improve the dimensional accuracy of the wheel as much as possible in a casting stage and overcome the problems such as parting-line flashes and adhesion of aluminum. If this problem can be overcome, the service life of the mould can be prolonged, labor hours and consumed materials can be saved in a machining process, the manufacturing cost of the wheel can be reduced, the utilization ratio of metals can be increased, and the profitability of enterprises can be improved.